To convert trigonometric angles in Radians, multiply by Math.PI/180. This will convert degrees to radians.
The following is the code −
using System; class Program { static void Main() { Console.WriteLine(Math.Cos(45)); double res = Math.Cos(Math.PI * 45 / 180.0); Console.WriteLine(res); } }
Above, we converted using the following formulae −
Math.PI * angle / 180.0